Theansungnoen Tinnakorn, Maijaroen Surachai, Jangpromma Nisachon, Yaraksa Nualyai, Daduang Sakda, Temsiripong Theeranan, Daduang Jureerut, Klaynongsruang Sompong
Protein and Proteomics Research Center for Commercial and Industrial Purposes (ProCCI), Faculty of Science, Khon Kaen University, Khon Kaen, 40002, Thailand.
Department of Biochemistry, Faculty of Science, Khon Kaen University, Khon Kaen, 40002, Thailand.
Protein J. 2016 Jun;35(3):202-11. doi: 10.1007/s10930-016-9662-1.
Known antimicrobial peptides KT2 and RT2 as well as the novel RP9 derived from the leukocyte extract of the freshwater crocodile (Crocodylus siamensis) were used to evaluate the ability in killing human cervical cancer cells. RP9 in the extract was purified by a combination of anion exchange column and reversed-phase HPLC, and its sequence was analyzed by mass spectrometry. The novel peptide could inhibit Gram-negative Vibrio cholerae (clinical isolation) and Gram-positive Bacillus pumilus TISTR 905, and its MIC values were 61.2 µM. From scanning electron microscopy, the peptide was seen to affect bacterial surfaces directly. KT2 and RT2, which are designed antimicrobial peptides using the C. siamensis Leucrocin I template, as well as RP9 were chemically synthesized for investigation of anticancer activity. By Sulforhodamine B colorimetric assay, these antimicrobial peptides could inhibit both HeLa and CaSki cancer cell lines. The IC50 values of KT2 and RT2 for HeLa and CaSki cells showed 28.7-53.4 and 17.3-30.8 µM, while those of RP9 were 126.2 and 168.3 µM, respectively. Additionally, the best candidate peptides KT2 and RT2 were used to determine the apoptotic induction on cancer cells by human apoptosis array assay. As a result, KT2 and RT2 were observed to induce apoptotic cell death in HeLa cells. Therefore, these results indicate that KT2 and RT2 with antimicrobial activity have a highly potent ability to kill human cervical cancer cells.
已知的抗菌肽KT2和RT2以及从暹罗鳄（Crocodylus siamensis）白细胞提取物中获得的新型肽RP9被用于评估其杀伤人类宫颈癌细胞的能力。提取物中的RP9通过阴离子交换柱和反相高效液相色谱相结合的方法进行纯化，其序列通过质谱分析。该新型肽能够抑制革兰氏阴性霍乱弧菌（临床分离株）和革兰氏阳性短小芽孢杆菌TISTR 905，其最小抑菌浓度（MIC）值为61.2 μM。通过扫描电子显微镜观察，发现该肽可直接作用于细菌表面。使用暹罗鳄白细胞素I模板设计的抗菌肽KT2和RT2以及RP9进行了化学合成，以研究其抗癌活性。通过磺酰罗丹明B比色法测定，这些抗菌肽能够抑制HeLa和CaSki癌细胞系。KT2和RT2对HeLa和CaSki细胞的半数抑制浓度（IC50）值分别为28.7 - 53.4 μM和17.3 - 30.8 μM，而RP9的IC50值分别为126.2 μM和168.3 μM。此外，最佳候选肽KT2和RT2通过人类凋亡阵列分析用于确定对癌细胞的凋亡诱导作用。结果显示，观察到KT2和RT2可诱导HeLa细胞发生凋亡性细胞死亡。因此，这些结果表明具有抗菌活性的KT2和RT2具有高效杀伤人类宫颈癌细胞的能力。
